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Hub-tip radius ratio transonic turbine for secondary flow - stator configurations designed to eliminate blade wakes and secondary-flow effects
Hub-tip radius ratio transonic turbine for secondary flow - turbine with low-velocity turning stator and standard rotor
The knowledge gained from previous experiments and reports was utilized for the construction of a dynamometer hub for 200 mkg (134.4 ft.-lb.) and 1200 kg (2646 lb.) thrust suited for a Liberty "12" engine. A reversing device is also described.
This purpose of this report is to provides details of the measurement of the control system stiffness of the UH-60A rotor hub mounted on the Large Rotor Test Apparatus (UH-60A/LRTA). The UH-60A/LRTA was used in the 40- by 80-Foot Wind Tunnel to complete the full-scale wind tunnel test portion of the NASA / ARMY UH-60A Airloads Program. This report describes the LRTA control system and highlights the differences between the LRTA and UH-60A aircraft. The test hardware, test setup, and test procedures are also described. Sample results are shown, including the azimuthal variation of the measured control system stiffness for three different loadings and two different dynamic actuator settings. Finally, the azimuthal stiffness is converted to fixed system values using multi-blade transformations for input to comprehensive rotorcraft prediction codes.
Rotor-hub bending moment measurements on hingeless rotor helicopter during abrupt maneuvers near ground
Data and performance of flow generation rotor and single-slotted 0.75 hub diffusion factor stator
Test on overall and blade element performance of single slotted 0.65 hub diffusion factor stator with self energized blowing boundary layer control
Boundary layer hub diffusion-factor stator blowing technique
Boundary layer bleed techniques for high lift stator blades, with hub diffusion factor stator performance data
Performance tests on slotted hub diffusion factor stator with boundary layer bleed
Lightweight rotor hub design for Mars landing autogyro
Experimental data and performance of honeycomb rotor shroud configuration to improve stall margin of 0.5 hub tip ratio single stage compressor
Flow distribution data for solid and honeycomb rotor shrouds to improve stall margin of 0.5 hub tip ratio single stage compressor
Design and performance of 0.9-hub-tip-ratio axial flow pump rotor with blade-tip diffusion factor of 0.63
Performance tests and efficiency measurement of hub-slit-suction stator in single stage compressor
A 22.9-centimeter diameter axial flow rotor with a 0.8 hub-tip radius ratio, a design flow coefficient of 0.466, and a blade tip design diffusion factor of 0.55 was tested in cold water under both cavitating and noncavitating conditions. Radial surveys of the flow conditions at the rotor inlet and outlet were made. At design flow, the rotor produced an overall headrise coefficient of 0.360 with an overall efficiency of 95.0 percent. The efficiency remained greater than 88 percent over the entire flow coefficient range which varied from 0.350 to 0.615.
Wind tunnel tests to determine the dynamic characteristics of hingeless rotors with hub moment feedback controls and to acquire experimental hingeless rotor transfer functions are discussed. Rotor transfer functions were calculated from data acquired during open loop frequency response tests. The transfer functions are linear and present the rotor longitudinal and lateral frequency responses to collective pitch, longitudinal cyclic pitch, and lateral cyclic pitch. The theoretical analysis was based on the rigid blade flapping model coupled with appropriate control system and cyclic pitch actuator equations of motion.
The test obtained from wind tunnel tests of a rigid rotor with hub feedback controls are presented. Four types of tests were conducted and the data from each are presented in separate appendices. The data are presented in the form of tables and charts.